Improvement in duplex wrench



Cibti'trd Ctatrs @met tlijirr.

A. B. DAVIS, OF PHILADELPHIA, PENNSYLVANIA, ASSIGNOR TO HIMSELF AND IVILLIAM C. EWING, OF SAME PLACE.

Letters Patent No. 94,085, dated August 24, 1869;

IMPROVEMENT IN DUPLEX WRENCH.

The Schedule referred to :in these Letters Patent and making part of the same.

To all whom it may concern:

Be it known that I, A. B. DAVIS, of Philadelphia, county of Philadelphia, and State of Pennsylvania, have invented an Improved Duplex Wrench; and I do hereby' declare the following to be a full, clear, and exact description of the saine.

My invention consists of a wrench, constructed in the pecular manner fully described hereafter, so that it may be'used as an ordinary wrench for square or six-sided nuts, Sac., as well as for cylindrical objects.

In order to enable others skilled in the art to make and use my invention, I will now proceed to describe its construction and operation, reference being had to the accompanying drawing, which forms a part of this specification, and in which- Figures l and 2 are exterior views of my improved duplex wrench;

ignre 3, a sectional plan, on vthe line .1-2, fig. 1; an

Figure 4, a sectional View of a portion of the wrench, drawn to an enlarged scale. l Similar letters refer to similar parts throughoutthe several views.

The shank A of the wrench is flattened upon its opposite sides, as vbest observed in iig. 3, has screwthreads c, and is furnished at one end with a suitable handle, b, while atits opposite end is the double permanent jaw B.

The movable jaw Bis arranged to slide upon the shank A, and `has a slot, c, through which the said shank passes, of such a `form that while it will prevent the jaw from turning upon the shank, it will permitit to have a slightplay or vibration upon the same. (See figs. 3 and 4.)

From the jaw B project the two arms ff', one on each side of the shank, the two arms terminating in a `yoke, D, which is valso arranged to slide freely upon the shank, the yoke containing a nut, F, the internal thread of which is adapted to the thread a on the shank, so that the jaw B maybe moved from or toward the jaw B, according to the direction in which the nut is turned.

On the bevelleil face h of the movable jaw are formed seri-ations or teeth, opposite to the teeth on the stationary jaw B, the two sets of teeth being cnt in such a manner that their points shall be directed toward each other, as clearly illustra-ted in iig. 4.

A spring, Ii, which is secured to the arm f and arl ranged to bear against the shank, has a tendency to maintain the movable jaw in the position shown in figs. land 3, or, in other words, in such va position that the endxofthe slotcshall bear against the shank, this being the position in which (after the adjustment ot the wrench) the serrated ends ot' the jaws are main tained at the greatest distance apart from each other.

Any force tending to compress the spring i, and to move the jaw B in the direction of the arrow, iig. 1,

vwill cause the serrated surface ofthe movable jaw to approach that of the stationary jaw.

\Vhen a round pipe, suoli as that represented bythe red lines y in tig. 4, or other cylindrical object is tobe grasped and turned by the wrench, the movable jaw is adjusted, by means ofthe nut F, until the obje'ct is .above and below, so as to admit of the free vibration of the jaw B'.

While the instrument is a most available one for turning cylindrical objects, it is noue the less serviceable' as an ordinary wrench, for square or six-sided nuts, 85o., for the projecting portions m m. of the two jaws will act on such objects in the same manner as those of ordinary wrenches.

Y I claim as my invention, and Letters Patentdesire to secure by A duplex wrench, consisting of' the screw-shank A,

its permanent serrated jaw B, the slotted serrated jaw B', its arms ff', and yoked), enclosing the nut F and the spring fi, the whole being arranged and operating as herein described.

In testimony whereof, I have signed my name to this specification, in the presence of two subscribing witnesses.

' A. B. DAVIS.

Witnesses:

JOHN WHITE, HARRY SMITH. 

